.sidebar-nav {
  margin-top: 20px;
  padding: 0;
  list-style: none;
}

body {
    background: #f5f5f5;
    font-family: '微软雅黑', Arial, sans-serif;
    margin: 0;
    padding: 0;
}

.main-nav {
    background: #1976d2;
    color: #fff;
    padding: 0 40px;
    height: 60px;
    display: flex;
    align-items: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.main-nav a {
    color: #fff;
    text-decoration: none;
    margin-right: 32px;
    font-size: 18px;
    font-weight: 500;
    transition: color 0.2s;
    padding: 0 8px;
    line-height: 60px;
}

.main-nav a:hover {
    color: #ffeb3b;
}

.container {
    max-width: 600px;
    margin: 48px auto 0 auto;
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 4px 24px rgba(0,0,0,0.08);
    padding: 40px 48px 32px 48px;
}

h1, h2, h3 {
    color: #1976d2;
    margin-top: 0;
    font-weight: 700;
    letter-spacing: 1px;
}

ul {
    padding-left: 20px;
}

li {
    margin-bottom: 10px;
    font-size: 17px;
}

p {
    margin: 12px 0;
    font-size: 17px;
}

a.btn, button, .btn {
    background: #43a047;
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 8px 20px;
    font-size: 16px;
    cursor: pointer;
    margin-right: 8px;
    transition: background 0.2s;
    text-decoration: none;
    display: inline-block;
}

a.btn:hover, button:hover, .btn:hover {
    background: #388e3c;
}

.btn-danger {
    background: #e53935;
}

.btn-danger:hover {
    background: #b71c1c;
}

input, select, textarea {
    border: 1px solid #bdbdbd;
    border-radius: 5px;
    padding: 7px 12px;
    font-size: 16px;
    margin-bottom: 12px;
    width: 100%;
    box-sizing: border-box;
}

form {
    max-width: 400px;
    margin: 0 auto;
}

.card {
    background: #fafafa;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
    padding: 24px 32px;
    margin-bottom: 24px;
    font-size: 18px;
}

.card h3 {
    margin-top: 0;
    color: #1976d2;
}

textarea {
    font-size: 16px;
    border: 1px solid #bdbdbd;
    border-radius: 5px;
    padding: 7px 12px;
    margin-bottom: 8px;
}
